The invention relates to an electric reflector lamp provided with
a reflector body with a concave light-beam shaping surface having an optical axis, which reflector body has a light emission window which is closed off with a light-transmitting cover, PA1 a light source on the optical axis, accommodated in a lamp vessel which is closed in a gastight manner, PA1 a lamp cap provided with contacts and connected to the reflector body, current conductors which connect the light source to respective contacts of the lamp cap, PA1 the light-beam shaping surface being subdivided into axial lanes. PA1 the axial lanes are plane transverse to their axial direction and give the light-beam shaping surface cross-sections transverse to the optical axis which are regular polygons, PA1 a first zone remote from the light emission window has half the number of axial lanes which a second zone adjacent the light emission window has.
Such an electric reflector lamp is known from EP-A 0 543 448 (PHN 13.900).
The known reflector lamp may have electrodes in an ionizable filling or an incandescent body as its light source.
The known lamp was found to yield a light beam in which differences in brightness between portions of the incandescent body become evident in the presence of an incandescent body as the light source, so that the beam is inhomogeneous. With a discharge arc between electrodes in an ionizable filling, differences in brightness may also arise in the beam, for example owing to a current conductor which extends alongside the discharge arc. With a high-pressure metal halide discharge, the lamp provides an illuminated field in which colour differences occur. When the lamp radiates predominantly upwards, the colour pattern is different from the pattern when it radiates predominantly downwards. The shape of the generated light beam, in addition, strongly depends on the position occupied by the discharge are in the reflector body.